1. Overview & Physics
Thermodynamics of Green Beans
Green coffee beans differ in cell density based on growing altitude. High-altitude beans (SHB/Strictly Hard Bean) are dense, with compact structures. During roasting, these beans conduct heat differently than soft, low-altitude beans. High density allows the core to heat up uniformly via conduction, whereas low-density beans risk surface scorching if heat is applied too rapidly.
Thermal Tuning
Charge your dense green beans at a higher temperature to drive heat efficiently to the center, keeping convection rates balanced.
2. Practical Calibrations
Managing this requires measuring indicators in real time. Adjust grind size, water dynamics, and flow parameters incrementally. Change only one variable at a time to ensure clean results and isolate target parameters.
Barista Action Checklist
- Weigh dry grounds dry dose exactly to 0.1g.
- Calibrate water temperature using PID sensors.
- Target correct brew ratios (e.g. 1:15 for filter, 1:2 for espresso).
- Swirl or stir to ensure even saturation during extraction.
- Record extraction time and evaluate flavor notes subjectively.
Frequently Asked Questions
How does bean density affect roasting?
Dense beans have tighter cellular structures, which transfer heat more uniformly but require higher initial thermal energy to roast correctly.
What is thermal conductivity in coffee?
It is the rate at which heat transfers from the bean exterior to its core. Moisture content acts as a thermal conductor during the drying phase.
